Compound and rotational damping in warm deformed rare-earth nuclei

The gamma decay in the quasicontinuum from selected configurations of the rotational nucleus 163Er has been measured with the EUROBALL array. A new analysis technique has allowed for the first time to directly measure the compound and rotational damping widths Gamma (micro) and Gamma (rot). Values of Gamma (micro) approximately 20 keV and Gamma (rot) approximately 200 keV are obtained in the spin region I approximately 30-40 variant Planck's over 2pi, in good agreement with microscopic cranked shell model calculations. A dependence of Gamma (micro) and Gamma (rot) on the K-quantum number of the nuclear states is also presented.     

Measurement of η photoproduction on the proton from threshold to 1500 MeV

Beam asymmetry and differential cross-section for the reaction γp → ηp were measured from production threshold to 1500MeV photon laboratory energy. The two dominant neutral decay modes of the η -meson, η → 2γ and η → 3π⁰ , were analyzed. The full set of measurements is in good agreement with previously published results. Our data were compared with three models. They all fit satisfactorily the results but their respective resonance contributions are quite different. The possible photoexcitation of a narrow state N(1670) was investigated and no evidence was found.